Update: WSSC Installs Temporary Bypass at Piscataway Wastewater Treatment Plant

Drinking Water System Not Affected

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Laurel – February 13, 2017 – Working long hours throughout the weekend, WSSC crews and contractors successfully installed temporary pumps and bypass pipes (see photos on right) at the Piscataway Wastewater Treatment Plant in Accokeek. The bypass diverts the majority of the wastewater flow directly into the plant for treatment following the rupture of a pressurized sewer main last Thursday. The remainder of the flow is being pumped into retention basins on plant grounds, a process that began Thursday evening to contain the overflow, and will be treated at a later date.

Late Sunday afternoon, the pumps were put into service to move wastewater through 2,000 feet of temporary pipe connected directly to the plant’s treatment system. Another 2,000 feet of temporary pipe is currently under construction and is expected to be operational in two to three days. The completion of this temporary piping will allow all wastewater to bypass the broken main and go directly into the plant for treatment.

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A third section of temporary pipe will then be constructed to carry additional flow as needed. The Piscataway Plant treats about 24 million gallons of wastewater per day.

Repairing the broken sewer main will be a long, complex process. The pipe is located under a concrete-encased structure that contains approximately 120-feet of high-voltage lines. The lines have been de-energized to allow crews to break through the concrete and safely relocate the high-voltage wires. Once relocation is completed, crews can excavate in the area of the broken pipe to determine the extent of the repairs. Until crews visually inspect the damaged pipe, a timeframe for repairs is not yet known.

It is estimated that 3.3 million gallons of untreated wastewater overflowed into Piscataway Creek on Thursday. The overflow into the creek was stopped late Thursday at approximately 11:20 p.m., when temporary pumps were set up to move the wastewater into the on-site retention basins. On Saturday, the bypass pumps became partially clogged with rags, causing an additional 540 gallons of untreated wastewater to go into Piscataway Creek. This is an ongoing overflow and the total volume will be calculated once repairs are complete.

Twenty-six signs have been posted in the area of the overflow, along the Piscataway Creek. WSSC has been in continuous communication with officials from MDE and the Prince George’s County Health Department, on site and over the phone, and will take all appropriate measures to clean up the affected area when repairs are complete.

It is important to note that WSSC’s water and wastewater systems are separate. This overflow is NOT affecting WSSC’s drinking water.

WSSC is committed to protecting the health of the public and the environment. With more than 5,500 miles of sewer mains throughout its service area, WSSC appreciates notification from citizens if a sewer back up or water main break is suspected. Please call our 24-hour Emergency Call Center at 301-206-4002 to report water or sewer emergencies in Montgomery or Prince George's counties. Customers can also report emergencies via email at emergencycallcenter@wsscwater.com and those customers who have smart phones can report emergencies using the WSSC Mobile App.